One note, and I agree with @Wildflower, I have found that Cliff Bloks are a little tougher to use in the winter because the cold temperature impacts the consistency, making them much firmer and a little harder to eat if you're running at pace. This isn't an issue during warmer months because they're much softer and easier to chew.
I have recently tested out Maurten. They're really easy to eat, work very well, and the flavor is OK but they're definitely on the expensive side. Their packaging is also pretty bulky... normal volume of gel but with a lot of air in the packaging which I am not sure I understand the reason for. It is really tough to wedge them into the purpose-built gel loops on my SPIbelt and they take up quite a bit of room if I toss them in the pouch.